Borehole tool



a shred Sept. 22, 1942 Search ileum M UNITED STATES PATENT OFFICE BOREHOLE TOOL Whitman D. Mounce, Houston, Tex., assignor to Standard Oil Development Company, a corporation of Delaware Application December 29, 1941, Serial No. 424,801

6 Claims.

The present application is directed to a device particularly suitable for locating casing seats in oil wells, as well as joints of pipe having a low magnetic permeability, for example, joints of aluminum or magnesium pipe in casing.

It is an object of the present invention to devise a wire line suspended tool which will signal to an operator at the surface of the earth the location of the casing seat or a joint of casing of poor magnetic permeability Within a borehole.

Other objects and advantages of the present invention may be seen from a reading of the following description taken in conjunction with the drawing, in which- Fig. 1 is an elevation of an embodiment of the present invention;

Fig. 2 is a fragmentary view of the embodiment shown in Fig. 1, with parts in a difierent position than in Fig. 1; while Fig. 3 is a sectional view taken along line III-III of Fig. 1.

It may be stated briefly that the device of the present invention comprises a body provided with looking dogs. The body is provided with slidably arranged actuating means provided with locking mechanisms and spring spacers arranged to bear against the casing through which the device is to be longitudinally moved. If the device is below the casing or is adjacent a joint of aluminum or magnesium pipe the operator will feel no resistance when he gives the cable suspending the device several short up and down strokes. On the other hand, if the device is in magnetically permeable material, such as steel casing, a short up and down stroke will act to set the locking dogs so that the operator can feel the line slack, and a subsequent stroke will release the dogs and allow the device to be lowered further into the borehole.

Generally speaking, the device is utilized by lowering it at the end of its suspending cable until it is at the approximate position the operator expects to find a length of magnesium or aluminum pipe, or the lower end of a string of steel casing. When this position has been reached, the operator stops the downward motion of the device and gives it a short reciprocating motion. If the dogs lock, the operator will feel the weight on the cable slacken, and will know that the tool is adjacent steel casing. If there is no slackening oi the cable, the operator will know that the tool is either below the lower end of the casing or opposite a joint of nonmagnetically permeable pipe, and will accordingly move the tool along the borehole and periodically give the cable a short up and down stroke in order to precisely locate the casing seat or the section of the nonmagnetically permeable casing.

Referring now specifically to the drawing, a body H is suspended from a wire line l2. Near the upper end of body ll locking dogs I3 are mounted on pivots M, so that they may assume either a collapsed or an extended position. Some distance below locking dogs l3 an arm I5 is attached to the body by pivot l6. To the lower end of the arm is attached permanent magnets ll, while the upper end of the arm is shaped to form a portion of a catch that is designated l8.

A slidable unit I0 is arranged on said body comprising an upper collar l9, a lower collar 20, and spacing springs 2i arranged to secure the collars so that they will slide simultaneously and, in addition, extending outwardly to frictionally contact the casing in which the device is to be moved. Attached to upper collar I9 is a catch 22 arranged to cooperate with catch I8 when the device is not adjacent magnetically permeable material.

Another locking means between the slidable member and body II is provided, comprising, as illustrated in detail in Fig. 3, a star wheel 23 secured to collar 20 by a pivot 24, and a cam surfaced member 25 arranged in groove 26 in body [I and secured by suitable fastening means, such as rivets 21.

Cam surfaced member 25 is arranged in body II so that body ll forms a projecting ledge A at the upper end of member 25. Member 25 is also provided with a smaller ledge B. When star wheel 23 is in the position shown in Fig. 3

and then is moved upward with respect to body.

H, the movement meets no resistance until the star wheel rests against ledge A. If from this position star wheel 23 is now moved downward with respect to body l l the cam surfaces of member 25 cause movement of the star wheel so that when it reaches its lower position a subsequent upward movement of the star wheel with respect to body H causes the star wheel to rest against ledge -B, preventing any additional upward movement. If the star wheel is now moved downwardly again, it returns to the position illustrated in Fig. 3, and the subsequent upward movement of the star wheel with respect to body I l allows the star wheel to move upward until it comes in contact with ledge A. Briefly then, star wheel 23, when moved longitudinally upwardly with respect to body I I will, on one stroke,

assume a position adjacent ledge A, and on a subsequent stroke will be brought to rest against ledge B.

Preparatory to placingthe device in the borehole, catches l8 and 22 may be locked together or, alternatively, star wheel 23 may be placed in the position bearing against ledge B. The device may then be lowered rapidly to the desired depth. The spacing springs 2| are, of course, arranged so that they will frictionally engage the casing. After the device is lowered the desired depth an upward pull is given wire line I2. This pull causes body H to move upwardly with respect to slidable member ID and brings the star wheel into the position illustrated in Fig. 3. Cable I2 is then slackened off and star wheel 23 travels upwardly to rest against ledge A. When in this upward position collar I9 is raised to assume the position shown in Fig. 2, extending dogsl3 against the casing so that the device is suspended by the locking dogs. The operator can easily tell when this condition exists by the slackening of wire line l2. Tension is then placed on wire line [2, body H raised, and the device then lowered. This second movement causes star wheel 23 to rest against ledge B, so that dogs 13 are collapsed and allow the tool to move downward.

Whenever the device is lowered beyond the bottom of the casing or adjacent a length of aluminum or magnesium pipe, the weight of magnet ll keeps arm l5 hanging downwardly so that latch I8 and latch 22 engage, and prevent any substantial relative movement between member Ill and body II. The operator can accordingly determine when the device isnot adjacent steel or iron casing, because when magnet I1 is adjacent nonmagnetically permeable material the dogs l3 will remain collapsed, whereas when magnet I1 is adjacent magnetically permeable material, the dogs I3 may be extended to suspend the device upon proper manipulation of the wire line l2.

While I have disclosed a specific embodiment of the present invention, it will be obvious that various changes may be made without departing from the scope of the invention. For example, while I have disclosed a particular type of latching mechanism, comprising star wheel 23 and cam surfaced member 25, various other similar locking mechanisms are well known to the art and may be substituted therefor. It is accordingly not my intention to be limited by the specific embodiment herein disclosed, but to be restricted only in accordance with the invention embraced by the hereto appended claims.

I claim:

1. A borehole tool comprising, in combination, a body, dogs pivoted to said body arranged to be outwardly extended from and to be collapsed toward said body, an actuating means arranged on said body to extend said dogs when in a first position, and to allow said dogs to collapse when in other positions, and locking means arranged to release said actuating means to said first position when adjacent a magnetically permeable body, and to lock it away from said first position when not adjacent a magnetically permeable body.

2. A borehole tool comprising, in combination,

a body, dogs pivoted to said body arranged to be outwardly extended from and to be collapsed toward said body, an actuating means slidingly arranged on said body to extend said dogs when in a first position and to allow said dogs to collapse when in other positions, a pivoted arm attached to a permanent magnet arranged to pre-'- vent a substantial amount of relative longitudi nal motion between said body and said actuating means when the magnet is not adjacent a magnetically permeable body, and to release said actuating means for a substantial amount of relative movement with respect to said body when adjacent a magnetically permeable body, and locking means arranged to be manipulated from the surface through a wire suspending line whereby said actuating means may optionally be made to extend said dogs and to be locked in position with said dogs collapsed.

3. A borehole tool comprising, in combination, a body, dogs pivoted to said body arranged to be upwardly suspended from and to be collapsed toward said body, a collar slidingly arranged below said dogs for suspending said dogs, magnetically operated locking means arranged on said body to prevent substantial longitudinal movement of said collar when said locking means is not adjacent a magnetically permeable body, and to release said collar for relative longitudinal movement when said locking means is adjacent a magnetically permeable body, a second locking means mechanically linked to said collar, comprising spacing springs adapted to frictionally engage the-casing in which said tool is lowered, a cam surface and a pivoted cam arranged to release said collar whereby said dogs are extended upon a relative reciprocating motion between said spring and said body, and whereby said collar is looked upon a second reciprocating motion so that said dogs may assume a collapsed position.

4. A bore hole tool comprising, in combination, a body, means secured to said body adapted to restrain the movement thereof, means arranged 'to activate said first mentioned means, and magnetic means mounted on said body and arranged to control the activation of said first means in response to the magnetic permeability of bodies adjacent the magnetic means.

' 5. A bore hole tool comprising, in combination, a body, releasable means secured to said body adapted to lock said body against vertical movement when in a well, a second means adapted to move said first means in a locking position, and a magnetic meansmounted on said body and arranged to prevent the operation of said second means when not adjacent a magnetic permeable body.

6. A bore hole tool adapted to be moved along the bore of a well comprising, in combination, a body, a releasable means secured to said body adapted to lock said body against vertical movement when in a well, a second means adapted to move said first means in a locking position, and a magnetic means mounted on said body and arranged to allow the operation of said second means when the body iswithin a cased portion of the well and to prevent the operation of said second means when the body is outside the casing.

WHITMAN D. MOUNCE. 

